Developing a process to evaluate construction project safety hazard index using the possibility approach in India

Hazard evaluation is a critical task in safety management of construction projects because of their characteristics and dynamics. This study provides a framework to evaluate the project hazard index (PHI), which represents the hazard level of a construction project by using the possibility approach (fuzzy set theory). To achieve this objective, the study has been conducted in two phases. In the first phase, 10 hazardous trades and their physical attributes have been shortlisted and a three-level hierarchical structure has been constructed to evaluate the PHI. In the second phase, the methodology of evaluation and determination of the weight of each hazardous trade with its attributes were carried out using tools such as fuzzy measures, fuzzy integrals, fuzzy analytical hierarchy process (FAHP), and the weighted sum method (WSM). Correlation between the PHI and safety budget of several project sites owned by the Delhi Metro rail project validates this study. The PHI will be useful to differentiate the projects based on their project hazard level and accordingly, decisions can be made to improve safety management in construction projects. Application of fuzzy measure and nonadditive fuzzy integral, nonprobability (possibility) approach, and considerations of trades instead of activities are some of the key highlights and contributions of this study.